Siblings of Sandy Hook Victims Face Trauma, Survivor's Guilt

"The more directly affected you are by a trauma and perceive it as scary -- like you almost died -- the harder time you have. They'll associate school with the shooting. It will be challenging and they will need support, but we do want to confront the things associated with the trauma, that's how we get over it," she said.

It will be vital in the next weeks for parents of surviving siblings to return the surviving child to a normal routine, including regular meals, sleeping, and physical habits, Howard and Briggs said.

"They need to make sure she's doing well in school and able to make and keep her friends, and then move on to celebrating (Noah's) life, and trying to find a way to honor him. This is going to shift as we get further away from the actual day of this horrible thing," Howard said.

"Children may demonstrate pretty severe bouts of anxiety, or clinginess, or reluctance to go to school when it reopens, or separate from their parents," Briggs said. "They may be more irritable, are crying more often, are more difficult to soothe. You'll see other children who experience a few days of disruption but very much get back into rhythm of life, the routine of life, which is very important for parents to keep up."

Briggs and Howard both noted that parents must try to create a stable environment for the child, and make them feel safe, even if the parents are dealing with trauma, too.

"It's time to call in all the reinforcements you have. Accept all those offers of help that get dismissed so often. If there's a grandparent, aunt and uncle, or sibling to come in relieve you from your primary duties, it is far better to bring in a beloved family member than it is to crack when undergoing such stress," Briggs said.

"You don't want to lie to child and say everything's fine, but it is really overwhelming to a child if you are sobbing daily and unable to keep thehome running. That sends them a message more than anything else that something is really wrong here," Briggs said.

If a child's appetite or sleeping habits change, or if they show any regressive behaviors, including wetting the bed or trouble separating from their parents, it may time to seek professional help, experts said.

Child pscyhologists, counselors, teachers, therapists, and clergy are all specially-trained professionals who can help deal with grief, and talking about the tragedy in a calm and supportive way will help the child most, Briggs said.

"The best thing to do in general is try to keep the routines of the family as consistent as possible, and try to convey the ability to keep them safe and confident in that, so you do not seem as anxious and distraught over it as you probably are," Briggs said. "If you're seeing some of these signs, can always wait a couple of days to see how it goes, but again, this is the moment to avail yourselves of help that is out there."